Sawing machine and control therefor



April 1 1924.

A. C. JACOBSON SAWING MACHINE AND CONTROL THEREFOR 3 Sheets-Sheet 1 Filed Nov. 2. 1922 FIG .2

A. c. JAcoBsoN SAWING MACHINE AND CONTROL THEREFOR Filed Nov. 2, 1922 3 Sheetsw-Sheet 2 M ii April 1 1924. 1,488,678

A. C. JACOBSON SAWING MACHINE AND CONTROL THEREFOR Filed Nov. 2, 1922 3 Sheets-Sheet 5 i-rnn,

Patented Apr. 1, 1924.

UNITED STATES FRY AXQEL C. JAC'OBSON, or SAN rnANcIsco, CAmron-rna, Assrenon TO T E normncn ELECTRIC sew oolvrr'Alvr, or sen .vnenorsco, Cannon-me, .e. coaroaarron.

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Application filed November 2, 1922. Serial No. 598,576.

7 '0 all whoa/z. it may concern:

Be it known that I, Axon]; C. JAooBsoN, a citizen of the United States, and a resident of San Francisco, county of San Francisco, and State of California, have invented certain new and useful Improvements in Sawing Machines and Controls Therefor.

The hereinafter described invention relates to that class of sawing mechanism wherein a circular saw is rotated in adjustably suspended condition to conveniently contact the object to be sawed, being of the type upon which United States Letters Patent No. 1,312,964, of August 12th, 1919, entitled Sawing machine were granted to Fred M. Easton. 1

The present invention embodies certain distinct and advantageous refinements not present in the aforesaid patent and has amongst its objects the provision of means whereby the saw is caused to rotate in the pivotal member holding same immediately when the said member is moved or released from its fixed or out of service position, so that by the time the saw is brought against the work to be performed it has gained the necessary momentum or speed to assure expeditious and efiicient cutting, difficulty having been encountered heretofore in satisfactory cutting, when the pivotal lever arm holding the saw was first brought into position closely adjacent the work and then the electrical connection made at the will of the operator to start the saw in revolution as covered in the construction of Patent No. 1,312,964.

Another object of the invention is to provide an electrical mechanism operable through the pivotal saw supporting lever arm for automatically controlling the opera tion of the electric motor used in driving the saw so that when the pivotal arm is confined against movement the electrical circuit to the motor will be closed, thereby effecting simple and efficient mechanism and control for the operator, and eliminating the necessity of having to carry the electrical connections on to the pivotal arm in operating the switch thereon to start the saw in motion as heretofore.

A further object of the invention is to fully house the saw driving mechanism in the pivotal member, thereby reducing to a minimum the accident hazard of open transmission parts and also permitting constant and efficient lubrication of the said transmission in a substantially tight case free from attack by the elements.

In order to fully comprehend the inventlon, reference is made to the accompanying drawings in which Fig. 1 is a side elevation of the fully assembled mechanism with the plvotal arm confined out of movement in which position the electric current is disconnected and the saw is at rest.

Fig. 2, is likewise a side elevation of the complete assembly in which position the saw is running, the electrical connection for starting being made immediately upon disconnecting the pivotal lever arm from the latch as shown.

Fig. 3, is an enlarged side elevation partly in section showing the breaking of the electrical connection in the switch upon securement of the pivotal arm (shown in dotted lines) and-the making of the electrical connection through the switchupon movement of the pivotal arm, (shown in solid lines) the latter operation setting the saw in motion.

Fig. 41 is a completely assembled front view of the device with the pivotal arm down to show the complete housing of the transmission carried by same.

Fig. 5 is an enlarged sectional view of the transmission shown as a bevel gear drive fully encased or housed.

Fig. 6 is a completely assembled view showing the machine as mounted in practical operation, the pivotal arm being down and the saw running.

Referring to the drawings, numeral 10 designates the pivotal saw carrying member, rotatable on the shaft, 11, the latter being journalled at the end of the fixed yoke, or member 12. The lower end of yoke, 12, is provided with a notched quadrant, 13, while bracketed to its opposite end is electric motor, 14:. Releasably confined to the pivotal member, 10, through engagement with the notch, 15, of quadrant, 13, is rod or pin, 16, constructed in the present instance to be lifted out of engagement therewith by movement of the handle, '17, towhich the rod, 16, is attached through crank pin, 18. Upon disengagement of the rod, 16, from the notch, 15, the pivotal member, 10, is free to move on shaft, 11, at the will of the operator. Located closely adjacent quadrant, 13, is switch, 19, with electrical connections leading to motor, 1%. Switch, 19, is provided with a push button, 20, against which spring, 21, is caused to hear so that a closed circuit is made through switch, 19, to motor, 1 1. Pivotal member, 10, is so arranged in relation to push button, 20, that upon engagement of the rod, 16, in notch, 15, it is brought to bear against push button, 20, pushing the same back against the spring, 21, and opening the electric circuit through the switch, 19, thereby shutting off the motor, 14. A switch, 22, is also provided for opening and closing the electric circuit from the power source but the control of the motor, 1%, in the rotation of the saw is effected entirely through switch, 19. The shaft, 11, which serves as a pivotal bearing for the member, 10, is rotated by motor, 14, through belt drive, 23, although any equivalent drive may be used. Aflixed to shaft, 11, is bevel gear, 24 and meshed therewith is bevel gear, To the end of bevel gear, 25, is secured an extended shaft, 26, and to the opposite end of shaft, 26, is affixed bevel gear, 27. Meshing with bevel gear, 2?, is bevel gear, 28, carried by shaft, 29, the latter being journalled in the end of pivotal member, 10, and secured directly on shaft, 29, is saw, 30. The housing, 31, completely encases the bevel gears, 2a and 25, on shaft, 11, while the housing, 32, entirely encloses the bevel gears, 27 and 28. The extended shaft, 26, between the bevel gears is fully enclosed in housing, 33, which also serves as a bearing for same. A counterweight, 34, is secured to the end of member, 10, beyond the pivotal shaft, 11, so as to facilitate the movement of the same, without undue exertion on the part of the operator. The device completely assembled is mounted on a supporting frame as shown in Fig. 6, which in the present instance is made of shafting with flanged floor supports, although angle iron or structural shapes may be used equally satisfactory as a support' ing frame upon which the saw may travel. It will also be noted that the push button switch, 19, is securely bracketed to the yoke, 12, and the electrical wires leading into the switch are covered with a helical wire spring to protect them. When the switch is opened and themotor, 14,.is stopped the yoke, 12, is heldin fixed position by a sliding latch at the end of rod, 16, as shown in dotted lines, Fig. 3.

It is obvious that minor changes can be made in the present construction without departing from the spirit of the invention, the scope of which covers a saw mounted in a pivotal lever member with means for setting the saw into motion when the pivotal lever member is moved from its releasably confined position, and means for completely housing the transmission between the shaft upon which the pivotalmember is moved and the saw shaft.

What I claim is.:

A sawing machine comprising an electric motor, a pivotal saw carrying member, transmission means betweenthe motor and the saw, an electric switch connected to the motor, means for releasably confining the pivotal member, said pivotal member controlling the switch in shut-off position and means whereby upon movement of the pivotal member from its releasably confined position the switch is closed for the passage of current to the motor.

AXCEL G. JACOBSON.

Witnesses:

G. CoLMAN,

T. D. Simmons. 

